The sentence 'Thank you for letting me know' is correct and usable in written English. You can use this sentence when someone has informed you of something. For example, "Thanks for letting me know that the meeting has been cancelled.".
Thank you for letting me know that someday, some employer may accept my unique contributions to the workplace, or even value them".
Thank you for letting me know that while I may think that I am dressing up for my Teacher Cadet lesson, I am in fact dressing to go to a night club or the whore house.
"Thank you for letting me know about the car," he said.
"Thank you for letting me know that the loud noise hurt your ears!
You are now and forever an Olympian and I thank you for letting me comment on you and let the world know a little more about what you have been going through for the past 8 days.
"Thank you for letting me go legit".
"Thank you for letting me win today".
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK